The reaction of carbon dioxide (CO2) with brine samples collected from the Oriskany Formation in Indiana County, PA, was investigated in an autoclave reactor under various conditions. A geochemical code, PHREEQC, was used as to simulate the reaction in the autoclave reactor. The combined experimental and modeling data suggests that pH (pH>9) plays a key role in the formation of carbonate minerals. The effects of temperature and CO2 pressure have a lesser impact on the formation of carbonate minerals. Published by Elsevier Ltd.